A capacitive touchscreen has a function called multi-touch. When multiple points on the touchscreen are touched simultaneously, multi-touch enables the touchscreen to recognize the points simultaneously. If multi-touch is used, various patterns formed using multi-touched points can be input to an electronic device such as a smartphone. Of the various patterns, only different types of patterns that are distinguished from each other can be used as identification marks.
However, the number of points that can be multi-touched is limited due to technological limitations. For example, multi-touch of a particular smartphone can recognize only about 2 to 5 points. The number of multi-touches may be more limited when a particular program screen, for example, a web browser is used. Therefore, the number of types of identification marks is limited. Accordingly, there are limitations in identifying more than a certain number of users or places using multi-touch based identification patterns. This has led to a need for a way to overcome limitations of an identification method using a multi-touch pattern.